In a trade in which much dust is produced there should be proper mechanical ventilation. The vacuum and plenum system should be employed. There is no factor in the industrial life more detrimental to the workman than that forcing him to breathe vitiated air laden with dust and other impurities produced by the processes employed in the trades.
The extremely dusty trades should be separated from the less dusty ones and special provision made to carry away the dust. It is often possible to substitute machinery for handwork in these trades. When the laborers are forced to work in very thick dust they may be protected in a measure by the use of respirators worn over the mouth and nose. These will catch some of the dust and act as filters.
It is often possible to place hoods directly above the machines in these trades and by means of a vacuum fan the dust is carried out through tubes.
The effects of dust upon the worker depend upon many factors. These might, however, be classified as conditioning factors in the individual and the character of the dust inhaled.
Dust from metals and minerals may produce mechanical injury to the membrane of the respiratory tract because of the sharp edges. Inhalation of dust might also bring about catarrhal conditions and coughs. There may be deposits of dust in the bronchi and even in the parenchyma of the lungs from long exposure to and inhalation of dust. This may result in consolidation and other conditions which may be purely adaptative on the part of Innate Intelligence to compensate for the presence of the foreign substances.
In F. Hoffman’s Bulletin of the Bureau of Labor, Vol. LXXIX, he gives the following classification of dusty trades according to the character of the dust produced:
“Group I—Exposure to Metallic Dust: Grinders, polishers, tool and instrument makers, jewelers, gold leaf and brass workers, printers, engravers and pressmen.
“Group II—Exposure to Mineral Dust: Stone, marble and cement workers, glass blowers, glass cutters, diamond cutters, potters, plasterers, paperhangers, moulders, core makers and lithographers.
“Group III—Exposure to Vegetable-fiber Dust: Cotton ginning, textile, linen, hemp, cordage and paper manufacturers, weavers, spinners, hosiery knitters, lace makers, jute and wood workers.
“Group IV—Exposure to Animal and Mixed Dust: Furriers, taxidermists, hatters, silk, wool, and worsted workers, carpet, rug, rag, and shoddy workers, hair mattress workers and upholsterers.”